With the currently well-known audio techniques, the studio-quality multi-channel digital signal is first converted to the analog form and then transferred to monitor loudspeakers with the per-channel electrical cables. A digital transmission method with electrical cables or optical fibers is also known. If the loudspeakers are passive, an additional amplifier for each loudspeaker is typically required to amplify the signal power at the transmitter and to feed the transmission cable line with enough power to drive the loudspeaker elements at the appropriate sound power level.
All these manipulations, as well as the physical analog transmission path itself, may inject several degrading effects, such as noise, interference, distortion, group delays, amplitude and phase errors, to the original signal. The cabling is also often rather clumsy and can be messy looking. With careful design of cables and their wiring layout, these effects can, at cost, be limited to some extent but seldom completely overcome. The number and bulkiness of the cables, the need for careful design and tedious installation work increase the costs as well as the required skills and time.
Cables and their connectors are further prone to mechanical faults, which are typically hard to find and fix. These problems are especially harmful in public performances when the performers and often even the audience move among the cables. Under these conditions, there exists a real hazard of harm and injury with the cabling. During artistic tours, the audio equipment is installed and uninstalled frequently to and from the varying environments, which multiplies these problems, efforts, and costs.
The use of active loudspeakers, having integrated and speaker element characteristics optimized amplifiers within them, simplifies the situation to some degree. The analog signals employed in such arrangements may be of lower power level and the more noise and interference resistant differential signaling can be readily employed. The generation of multi-channel differential signals requires, however, rather expensive, high-quality analog electronics plus costly differential cabling and connectors.
While a wireless distribution of audio signal(s) would enable dispensing with cables and connectors to a large extent, most of the currently available wireless audio distribution systems are either non-standard radio solutions or infrared solutions, typically using lossy audio compression methods thus resulting compromised audio performance. Moreover, wireless distribution is also prone to transmission errors providing a further challenge in provision of high-quality audio. They are therefore mainly used for supportive purposes, such as for rear speakers in home theaters.